M 20, the large area of glowing red and blue gas in this image,
is one of the most beautiful objects in the sky. The red area is
an expanse of hydrogen gas ionized and caused to glow by the radiation
of the multiple-star system near its center. It is crossed by several lanes
of dark, obscuring gas and dust which has given it its name. The blue section
is an area where the starlight simply reflects off the gas and interstellar dust.
In this image you can see that this reflection cloud is not separate, but a part
of and completely surrounding the area that glows red. M 20 is 40 light years
across, and 5200 light years away. It is located in Sagittarius, about 1.5
degrees north of M 8 (which is located off the left side of this image), and
they are both probably part of the same huge cloud of hydrogen.

The bright knot of stars in the upper right of this image is M 21, an open
cluster of about 70 stars.

This image also shows several bands of dust and gas which obscure the stars behind
them, and so appear as dark bands running through this area.

This image won the July 2007 Digital Astrophotography Group "Moderator Challenge" photo contest


Image data:
Camera: Canon 350XT (modified)
Exposure: ISO 800, 5 minutes x 30
Telescope: 10" Schmidt-Newtonian, Baader coma corrector